1. Field of the Invention
The present invention relates generally to telecommunications systems and methods for connecting to an automobile's electrical system via a cellular system, and specifically to sending messages, via the cellular system, to a unit interfaced with an automobile's electrical system instructing the unit to access and activate or deactivate specific electrical devices.
2. Background and Objects of the Present Invention
Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications ever. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world. A standardization group, European Telecommunications Standards Institute (ETSI), was established in 1982 to formulate the specifications for the Global System for Mobile Communication (GSM) digital mobile cellular radio system.
With reference now to FIG. 1 of the drawings, there is illustrated a GSM Public Land Mobile Network (PLMN), such as cellular network 10, which in turn is composed of a plurality of areas 12, each with a Mobile Services Center (MSC) 14 and an integrated Visitor Location Register (VLR) 16 therein. The MSC/VLR areas 12, in turn, include a plurality of Location Areas (LA) 18, which are defined as that part of a given MSC/VLR area 12 in which a mobile station (MS) (terminal) 20 may move freely without having to send update location information to the MSC/VLR area 12 that controls the LA 18. Each Location Area 12 is divided into a number of cells 22. Mobile Station (MS) 20 is the physical equipment, e.g., a car phone or other portable phone, used by mobile subscribers to communicate with the cellular network 10, each other, and users outside the subscribed network, both wireline and wireless. The MS 20 may also include a Subscriber Identity Module (SIM) card 13, or other memory, which provides storage of subscriber related information, such as a subscriber authentication key, e.g., the International Mobile Subscriber Identity (IMSI) number, temporary network data, and service related data (e.g. language preference).
The MSC 14 is in communication with at least one Base Station Controller (BSC) 23, which, in turn, is in contact with at least one Base Transceiver Station (BTS) 24. The BTS is the physical equipment, illustrated for simplicity as a radio tower, that provides radio coverage to the geographical part of the cell 22 for which it is responsible. It should be understood that the BSC 23 may be connected to several base transceiver stations 24, and may be implemented as a stand-alone node or integrated with the MSC 14. In either event, the BSC 23 and BTS 24 components, as a whole, are generally referred to as a Base Station System (BSS) 25.
With further reference to FIG. 1, the PLMN Service Area or cellular network 10 includes a Home Location Register (HLR) 26, which is a database maintaining all subscriber information, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information. The HLR 26 may be co-located with a given MSC 14, integrated with the MSC 14, or alternatively can service multiple MSCs 14, the latter of which is illustrated in FIG. 1.
The VLR 16 is a database containing information about all of the Mobile Stations 20 currently located within the MSC/VLR area 12. If a MS 20 roams into a new MSC/VLR area 12, the VLR 16 connected to that MSC 14 will request data about that Mobile Station (terminal) 20 from the HLR database 26 (simultaneously informing the HLR 26 about the current location of the MS 20). Accordingly, if the user of the MS 20 then wants to make a call, the local VLR 16 will have the requisite identification information without having to reinterrogate the HLR 26. In the aforedescribed manner, the VLR and HLR databases 16 and 26, respectively, contain various subscriber information associated with a given MS 20.
In many situations, a subscriber may desire to access and activate or deactivate electrical devices within his or her automobile, or other similar vehicle, such as a motor home, truck, tractor trailer, motorcycle, boat, or plane. For example, if the subscriber has accidentally locked their keys inside the car, parked the car and then not remember if the headlights were turned off or if the car doors were locked, or parked the car in a large parking lot and not remembered where it was parked, the subscriber may wish to have access to various electrical systems, such as door locks, headlights, and the engine. In addition, if the subscriber's car has been stolen, the subscriber may want to know the location of the car or alternatively, may wish to disable the car to prevent the thief from driving it. One convenient way of accessing such electrical systems would be to dial their MS within their car and instruct their MS to activate or deactivate specific electrical devices. Unfortunately, there is currently no existing way of interfacing an MS to an automobile's electrical system.
It is therefore an object of the invention to interface to and control an automobile's ignition and electrical systems via the cellular system.